I. Field of the Invention
This invention relates to an electric motors and more particularly to a method of cooling an electric motor used to drive a pump.
II. Description of the Related Art
Centrifugal pumps have large motors that require effective cooling to prevent overheating. Cooling systems known within the art use a motor coolant which circulates inside the motor housing in contact with components of the motor. Previous motors also contain a separate oil cooling system to pull heat directly away from the motor's housing. Typically, cooling oil is circulated within and through the motor. Heat exchangers are often used within circulating the cooling fluid.
One problem known in the art relates to the efficiency of cooling the oil used to cool the motor. One known method circulates cooling oil across a plate but does not fully segregate the oil prior to this. Thus the cooling oil is not cooled to the maximum degree of efficiency. What is needed is a system that fully separates the cooling oil thereby maximizing the heat transfer and thus the cooling of the cooling fluid.
Another problem related to known systems relates to the control of the flow of the cooling fluid. In particular, the cooling fluid flow rate is not controlled in any manner. Thus again the efficiency of the heat transfer process is not optimized. What is needed is a method of controlling the flow rate thereby fully controlling the heat transfer of the cooling fluid thereby better controlling the temperature control of the motor.
Another problem known in the art relates the physical characteristic of the cooling fluid. In particular, it is known that cooling fluids as they pick up heat from the motor they are cooling tend to expand. This expansion raises the pressure of the cooling fluid and if excessive can become dangerous. What is needed is a method that allows the cooling fluid to expand as necessary without increasing the pressure of the cooling fluid.
The present invention contemplates a new and improved oil cooled motor and pump apparatus which is simple in design, effective in use, and overcomes the foregoing difficulties and others while providing better and more advantageous overall results.